package cn.pku.sirx.snad.ads.strategy;

import java.util.List;

import cn.pku.sirx.snad.ad.model.UserContext;
import cn.pku.sirx.snad.ad.model.WeightedKeyword;

/**
 * Keyword selection.
 * 
 * @author WangXiao
 */
public interface IKeywordRetrievalStrategy {

	/**
	 * Retrieve keywords and calculate each weight.
	 * 
	 * @param userContext
	 *            UserContext
	 * @return selected keywords considering business values
	 */
	List<WeightedKeyword> retrieveKeywords(UserContext userContext);

}
